Silylalkoxymethyl halides are publicly known. Among these compounds, trimethylsilylmethoxymethyl chloride and phenyldimethylsilylmethoxymethyl chloride in particular are very important in the synthesis of bio-active substances and natural products with complex structures as reagents that protect functional groups containing active hydrogen.
Some examples of synthesis by several methods have already been reported for silylalkoxymethyl chlorides such as trimethylsilylmethoxymethyl chloride and phenyldimethylsilylmethoxymethyl chloride (See to Bruce H. Lipshutz et al., Tetrahedron Letters (Great Britain), Volume 21 (1980), pp. 3343-3346; Denis Guedin-Vunong et al., Bulletin de la Societe Chimique de France (France), No. 2 (1986), pp. 245-252; Arthur G. Schultz et al., Organic Preparations and Procedures International (US), Volume 27 (1995), pp. 572-574; and G. J. P. H. Boons et al., Tetrahedron Letters (Great Britain), Volume 31 (1990), pp. 2197-2200). These synthesis examples involve chloromethylation of the corresponding silyl alcohol using hydrogen chloride gas in the presence of a formaldehyde polymer.
However, there is a substantial problem to execute this procedure on an industrial basis. Specifically, the generation of by-product water cannot be avoided during chloromethylation using hydrogen chloride gas, and this water reacts with the product, resulting in product decomposition. The result is either a major reduction in the yield of the target silylalkoxymethyl chloride or a complete failure to obtain the target silylalkoxymethyl chloride.
In the aforementioned references, the by-product water is removed from the system by introducing a dehydrating agent, such as magnesium sulfate, immediately after the reaction. However, the implementation of this procedure on an industrial basis is cumbersome and complicated, and the product decomposition also proceeds during the time required to carry out the dehydration treatment. Moreover, the dehydrating agent must be separated from the product by, for example, filtration, which lengthens the process time, increases the amount of waste, raises the production costs, and lowers the yield.
In addition to the preceding, hydrogen chloride gas is a gaseous reagent and thus is much more difficult to handle than ordinary liquid reagents. It is difficult, in particular, to measure the amount used in the reaction, making it necessary to use a large excess of the gas and thereby raising the costs and increasing the amount of waste.
A. G. Shipov et al., Zhumal Obshchei Khimii (formerly the USSR), Volume 59 (1989), pp. 1204-1205, describes a method for manufacturing alkoxymethyl chloride by the reaction of an aryl alcohol or alkyl alcohol with formula (3)R—OH  (3)wherein R is phenylmethyl or an alkyl group having 1, 5, 8, 10 or 12 carbon atoms, with paraformaldehyde in chlorotrimethylsilane. However, this reference does neither describe nor suggest the use of a silyl alcohol as a starting material.